Synthesis and characterization of regioselectively substituted curdlan hetero esters with different ester groups on primary and secondary hydroxyl groups. (1st February 2018)

• Record Type: Journal Article
• Authors: Chien, Chih-Ying; Iwata, Tadahisa
• Is Part Of: Carbohydrate polymers. Volume 181(2018)
• Page Start: 300
• Page End: 306
• Publication Date: 2018-02-01
• Subjects: Cudlan -- Regioselectively hetero ester -- Detritylation -- Crystal structure; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2017.10.046
• Languages: English
• ISSNs: 0144-8617

Abstract

Graphical abstract: Highlights: A new method to remove trityl group from 6- O -trityl-curdlan without acyl migration was developed. Regioselectively substituted curdlan hetero esters, CD24Ac6Pr and CD24Pr6Ac, were synthesized. Ester groups on secondary hydroxyl groups are the determining substitutions to the melting behavior and crystalline formation of curdlan esters. Abstract: Two kinds of regioselectively substituted curdlan hetero ester, 2, 4-di- O -acetyl-6- O -propionyl-curdlan (CD24Ac6Pr) and 2, 4-di- O -propionyl-6- O -acetyl-curdlan (CD24Pr6Ac), were synthesized. By repeating detritylation and esterification, a new method to remove trityl group from 6- O -trityl-curdlan without acyl migration was developed. Their molecular structures, thermal and mechanical properties and crystal structures were analyzed by NMR, TGA, DSC, tensile test and WAXD. It was concluded that the ester groups substituted on secondary hydroxyl groups at C2 and C4 positions play the decisive role in the melting behavior and crystalline formation of curdlan esters. Also, the mechanical properties of curdlan esters are controllable by the adjustment on its molecular structures.